The present invention relates to fiber reinforced thermoplastic materials.
The production of thermoplastic material of poly(arylene sulfide) resins reinforced with unidirectional glass fibers by pultrusion has been disclosed. See, for example, U.S. Pat. No. 4,680,224. At least one fiber strand of continuous filaments is contacted with a poly(arylene sulfide) resin in the form of a powder or a slurry. The impregnated strand or strands are then pulled through a temperature controlled die for producing a composite which can have the form of, for example, a tape, a rod or a sheet.
The glass fiber reinforced pre-preg tapes produced in this manner are useful for such applications as structural members, aircraft parts, doctor blades, and the like.
For some applications the continuous fiber reinforced thermoplastic pre-preg tape will be more useful with improved transverse tensile strength and improved hydrolytic stability. For example, doctor blades used to process aqueous-based materials require materials of construction that have good hydrolytic stability and good transverse tensile. Likewise, structural members subjected to multi-directional high loads require materials of construction with, among other properties, good transverse tensile strength. Good transverse tensile strength also helps to eliminate continuous fiber composite microcracking, mitigates the propagation of microcracking under loaded conditions and improves resistance to fatigue.
Properties such as transverse tensile strength and hydrolytic stability in thermoplastic material of poly(arylene sulfide) reinforced with glass fibers have been improved by use of silanes. When the silanes are mixed with the poly(arylene sulfide) prior to application on the glass fiber it is important that the silanes are maintained at consistent concentrations in the poly(arylene sulfide)s during treatment of the glass fibers and that coating of the glass fibers be uniform.